Regulation of Botrytis cinerea Infection and Gene Expression in Cut Roses by Using Nano Silver and Salicylic Acid.

Suong Tuyet Thi Ha,Yong Ho Jeon,Hyong Woo Choi,Byung-Chun In,Yong-Tae Kim

doi:10.3390/plants10061241

Abstract

Botrytis cinerea (B. cinerea) is one of the necrotrophic pathogens resulting in the heaviest commercial losses in cut rose flowers, and the severity of gray mold disease partly depends on the presence of ethylene during the storage and transport. The effectiveness of nano silver (NS) and salicylic acid (SA) was assessed as a novel control agent in protecting the cut rose flowers against B. cinerea infection and ethylene damages. The efficacy of NS and SA was compared with an inoculated control (CON). A non-treated control (NT) was also used to evaluate the natural infection process. The results indicated that pretreatment with 20 mg L−1 NS significantly reduced B. cinerea growth in rose petals during vase periods. NS effectively suppressed the mRNA levels of ethylene biosynthesis genes (RhACS2, RhACS4, and RhACO1) and the reduction in expression levels of ethylene receptor genes (RhETR1, RhETR2, and RhETR5) and the downstream regulator RhCTR2 in rose petals after B. cinerea inoculation. NS application also decreased the expression of the B. cinerea snod-prot-like 1 (Bcspl1) gene which acts as the virulence factor in cut roses. In NS flowers, the maximum quantum yield of PSII (Fv/Fm) value was higher and the leaf temperature was lower on day 1, suggesting that these factors can be used for detecting B. cinerea infection and water stress in cut rose flowers. Furthermore, NS improved water relations and extended the vase life of cut rose flowers by 3.3 d, compared with that of NT flowers. In contrast, SA had no inhibitive effects on both B. cinerea growth and ethylene response in cut roses. The findings from the present study highlight NS as a promising new candidate for preventing B. cinerea infection and ethylene damages and for improving the postharvest quality of cut roses exported overseas.

Highlights

Roses (Rosa hybrida L.) are grown worldwide because of their fragrances, colors, and economic and ornamental values
Gray mold caused by B. cinerea, a necrotrophic pathogen, decreases the economic and ornamental value of cut roses during storage and transportation
Cut roses are still susceptible to B. cinerea infection even under very low temperature conditions because of latent penetration and ability to grow at low temperatures [12]

Summary

Introduction

Roses (Rosa hybrida L.) are grown worldwide because of their fragrances, colors, and economic and ornamental values. Cut rose flowers are prone to infection with gray mold disease which is caused by B. cinerea under suitable conditions such as high humidity and low temperature during export and distribution [1]. B. cinerea infection often appears and forms necrotic lesions on the petals and spreads to the entire flower, resulting in failure of the flower opening and petal abscission and complete loss of economic value [1,2,3]. Once the rose flowers are infected, the infection rapidly increases and is difficult to control. It is important to develop an effective method for suppressing gray mold disease and for improving postharvest quality of cut rose flowers

Methods

Results

Conclusion